can you get this to act up and see what the volt reading is at the fuse called TRANS fuse # ***** in the inside fuse box testing it with the truck running and it acting up as your testing it99 % of these trucks doing what yours is doing is caused by low voltage at that fuse which will cause the transmission not to shift correctly and the dash shift and tach and speedometer to quicka VERY common issue which is corrected by replacing the ignition switch and the ignition switches when they act up will NOT send a full 12 volts to that fuse causing this issuei can not stress enough that you need to truck acting up with it running when testing that fuse for voltsthe odds are it will be under 12 volts and if it is replacing the ignition switch will correct this issue 99 % of the time

the low voltage is from a bad ignition switchnot the lock cylinder but the electronic ignition switch that connects to the lock cylinder casereplacing the ignition switch in this truck will correct both problems you are having